Debatable Genius

There is some debate on the inventor of the cat flap or cat door,but it is most commonly thought that Isaac Newton should be credited. A rather funny story about his invention claims Newton made a large hole for the mother cat, (whose alleged name was Spithead) and a smaller hole for the kittens not realizing the kittens would follow the mother through the larger one. A neighbor of Newton's said "Whether the story is true or not there are in the door to this day two plugged holes of the proper dimensions for egress of cat and kittens". True or not it makes a fine story.
Today technology has made advances in cat doors,ranging from weighted flaps,magnetic flaps,to the more sophisticated electromagnetic flaps that detect a magnet on the cats collar. The top of the line cat flap has a reader to read a cat's microchip implant rather than the cat having to wear a collar.